The present invention relates to screwdrivers, and particular to a safety switch of a screwdriver which has a sample and easily assembled structure. Moreover, the safety switch can be used safely.
Screwdrivers are general tools for the carpenters and currently they become more useful for DAY (do-it-yourself) workers. In the prior art, the main concern in designing screwdrivers is the speed and convenience of the screwdriver, but recently, the safety use of screwdrivers becomes more and more important in design of the screwdrivers.
In one prior art, a slide seat is used to control the movement of a turning unit so as to control the triggering operation of the trigger by a first flange on the turning unit, thereby, a predetermined effect is acquired. In another prior art, a sliding seat resists against and rotates an elastomer 44 so that a buckling portion will shift a stop to rotate through a predetermined angle and thus the body of the screwdriver will trigger the trigger to have a predetermined effect.
In above said prior arts, there are so many components to make the structure too complicate. Thereby, the cost is high and the assembly work is tedious. As a result the yield ratio is low.
Accordingly, the primary object of the present invention is to provide a safety switch of a screwdriver which has a sample and easily assembled structure. Moreover, the safety switch can be used safety.
To achieve above object, the present invention provides a safety switch of a screwdriver having a driver body; the safety switch comprising: a push unit; a trigger pivotally installed on the driver body; a receiving space being formed within the trigger for receiving the push unit; a safety rod; one end of the safety rod being installed at a lower end of the driver body; and another end of the safety rod being installed below the trigger; the safety rod being movable into or out of the trigger for pushing the push unit. The push unit comprises: a torsion spring pivotally installed to the trigger; a resisting unit pivotally installed to the trigger; one end of the torsion spring resisting against the resisting unit and another end thereof enclosing a pin which is pivotally installed to the trigger; the ejecting unit having two ends; and a roller pivotally installed to the trigger and installed at a pushed end of a valve rod;
When the trigger is triggered firstly without pushing the safety rod, the roller will move and rotate to leave the push end of the valve rod so that the valve rod cannot be pushed and the screwdriver will not be triggered. When the safety rod is pushed firstly, the safety rod will resist against one end of the resisting unit so that another end of the resisting unit resists at one side of the roller. When the trigger is pressed, the roller cannot rotate because the roller is resisted against by resisting unit. Thus, the roller moves toward the pushed end of the valve rod so that the screwdriver is triggered.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.